1 /* $OpenBSD: inet_neta.c,v 1.7 2005/08/06 20:30:03 espie Exp $ */
2
3 /*
4 * Copyright (c) 1996 by Internet Software Consortium.
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
11 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
12 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
13 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
14 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
15 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
16 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
17 * SOFTWARE.
18 */
19
20 #include <sys/types.h>
21 #include <sys/socket.h>
22 #include <netinet/in.h>
23 #include <arpa/inet.h>
24
25 #include <errno.h>
26 #include <stdio.h>
27 #include <string.h>
28
29 /*
30 * char *
31 * inet_neta(src, dst, size)
32 * format an in_addr_t network number into presentation format.
33 * return:
34 * pointer to dst, or NULL if an error occurred (check errno).
35 * note:
36 * format of ``src'' is as for inet_network().
37 * author:
38 * Paul Vixie (ISC), July 1996
39 */
40 char *
inet_neta(in_addr_t src,char * dst,size_t size)41 inet_neta(in_addr_t src, char *dst, size_t size)
42 {
43 char *odst = dst;
44 char *ep;
45 int advance;
46
47 if (src == 0x00000000) {
48 if (size < sizeof "0.0.0.0")
49 goto emsgsize;
50 strlcpy(dst, "0.0.0.0", size);
51 return dst;
52 }
53 ep = dst + size;
54 if (ep <= dst)
55 goto emsgsize;
56 while (src & 0xffffffff) {
57 u_char b = (src & 0xff000000) >> 24;
58
59 src <<= 8;
60 if (b || src) {
61 if (ep - dst < sizeof "255.")
62 goto emsgsize;
63 advance = snprintf(dst, ep - dst, "%u", b);
64 if (advance <= 0 || advance >= ep - dst)
65 goto emsgsize;
66 dst += advance;
67 if (src != 0L) {
68 if (dst + 1 >= ep)
69 goto emsgsize;
70 *dst++ = '.';
71 *dst = '\0';
72 }
73 }
74 }
75 return (odst);
76
77 emsgsize:
78 errno = EMSGSIZE;
79 return (NULL);
80 }
81